Although there are many different jigs or devices made to make different size circles, there is no such item to make an arch. An arch differs from a circle in that it may vary in its proportions even as an elipse varies from a circle. This arch is not just an enlarged section of a circle, but may be a portion of an elipse. There are no other jigs available for purchase, that are made to cut arches with a router or other cutting tools.
In the production of decorative arches that are used at the top of a bookcase, for instance, the width of the bookcase determines the width of the arch. If there are varying size widths, one would need varying sized arches. If the difference in widths is large, for example 12xe2x80x3, a matching arch in a set of bookcases will be cut higher into one stock than on the other. If the center of the arch needs to maintain a reveal, such as 2xe2x80x3, the two arches will need to vary in their spread. This jig is able to adjust to that change quickly and readily. Consider the difference in the performance of a regular miter box and a compound miter box. Both will cut a single 45 degree angle, but the compound miter box can cut a compound miter required to solve specialized crown moulding installation problems. The latter would create a double angle cut. So it is with the arch cutting jig, in that it can cut an arch out of a compound-circle, rather than just a simple circle. For the cabinetmaker to make an arch with the use of present technology, he must use one of three methods. [1] He must freehand an arch on his work piece or pattern, [2] use a bent thin and narrow piece of wood to create the arch and trace it on his work piece or pattern, or [3] create a jig with a pair of nails and a string and using a pencil, trace the arch onto the work piece or pattern. Each of these present methods require him to draw, cut shape or sand to a finished product and possibly cut again if he is using a pattern, to finally get the desired result. At the end of a considerable amount of time he has one arch done. If the arches are to be all the same on the bookcase, this product can be used as a pattern as well as to cut the other arches from it. But if the arches vary, even by a few inches, one would have to go through this long process over and over again. It should be appreciated that there is a need for a quick, accurate, and easily adjustable arch cutting jig apparatus.
Method # 3 is a step above free-handing each arch for it allows you to create many accurately drawn arches. By taking two nails and tacking them into a piece of wood a specified distance apart you can then take a loop of string, whose diameter is larger than the distance of the two nails and circumvent the two nails, thus creating a jig. By putting a pencil against the upper edge of string, one can draw a perfect arch from nail to nail. The arch cutting jig apparatus uses this same principle to create a pathway for the cutting tool""s bit to follow. By using a cutting tool, it creates a 90 degree cut which thereby creates a finished product quickly and efficiently. This arch cutting jig apparatus fills the need that exists in the making of multi-sized arches.
There is a need today for a quick, efficient, and variable arch cutting jig. Rather than drawing and cutting arches by hand, this jig allows one to set up the desired arch and cut it quickly and cleanly with a router or other cutting device, creating a sharp detailed arch. Present methods allow one to only trace cut by hand, and refine with a sander to get to the desired product. This is tedious and time consuming, especially if there are multiple, varyingxe2x80x94sized arches to make.